Liquid fuel burner



Tune 29, 1954 K. H. MOODY 2,682,301

LIQUID FUEL BURNER Original Filed March 16, 1948 2 Sheets-Sheet l FIE.1.

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M/Z'H H. Mwmc June 29, 1954 K. H. MOODY LIQUID-FUEL BURNER 2 Sheets-Sheet 2.

Original Filed March 16, 1948 A f/w H. Mww I Patented June 29, 1954 LIQUID FUEL BURNER Keith H. Moody, Duluth, Minn., assignor to United States Steel Corporation, a corporation of New Jersey Original application March 16, 1948, Serial No. 15,233. Divided and this application January 4, 1951, Serial No. 204,337

2 Claims.

1 This application, which is a division of my copending application, Serial No. 15,233, filed March 16, 1948, now Patent No. 2,550,848, relates to a liquid fuel burner and more particularly to a burner for use in an open hearth furnace using scrap metal as part of the charge. In the operation of such furnaces, scrap is first charged into the furnace and melted down, after which cold and/or hot iron are added and the entire charge refined. Various types of fuel, such as gas, oil and tar, are used in heating th furnace. In some instances a combination of gas and oil or tar is used. This invention relates to those burners in which oil or tar are used separately or in combination with gas and for the purpose of this application, any fuel made up in whole or in part of a liquid will be termed liquid fuel. In heatingthe charge, the heat is supplied alternately from each end of the furnace and ordinarily a single burner is used at each end of the furnace.

Due to normal furnace construction and the relative position of the bridge walls and burners, it has been difficult to provide the air in a manner to obtain combustion of the liquid fuel close to the entrance end of the furnace when using a single burner at top capacity. As a result, a considerable amount of fuel burns near the exit end of the bath or may even burn as it leaves the furnace through the downtakes. I have found that by using a burner which introduces compressed oxygen directly below the fuel stream the speed of combustion is increased with an accompanying increase in melting rate and fuel efficiency.

It is an object of this invention to provide a liquid fuel burner in which means are provided for introducing oxygen into the combustion chamber directly beneath the fuel stream.

This and other objects will be more apparent after referring to the following specification and attached drawings, in which:

Figure 1 is a plan view, partly in section, of one-half of an open hearth furnace showing my burner in place;

Figure 2 is a longitudinal section of the furnace of Figure 1 taken through the front uptake;

Figure 3 is a longitudinal elevation of the burner of my invention;

Figure 4 is an enlarged longitudinal section of the burner of Figure 3;

Figure 5 is a sectional view taken on the line V-V of Figure 4; and

Figure 6 is a sectional view taken on the line VI-VI of Figure 4.

Referring more particularly to the drawings, the reference numeral 2 indicates the hearth of an open hearth furnace. The furnace is substantially symmetrical about its transverse center line and therefore only one-half thereof is shown in the drawings and will be described herein. A burner tunnnel l is provided through the end wall 6 and a liquid fuel burner 8 is arranged approximately on the center line of the furnace with its axis arranged at an angle to intersect the surface of the charge.

As shown in Figures 3 to 6, the burner 8 consists of a casing [0 inside of which near the top thereof is a conventional oil burner I: made up of three concentric pipes [4, IE and I8. Steam is supplied through the inner pipe [4 and oil is supplied through the pipe it around the pipe M. The oil passes through holes 2|] in pipe M at the nozzle 22 where it mixes with the steam in the usual manner. An air space is provided between the pipes l6 and I8. Beneath the oil burner I2 is a longitudinal pipe 24 which contains an oxygen supply pipe 26. The end of the pipe 26 extends beyond the end of the burner a distance of between one and twelve inches, preferably between six and twelve inches. A pipe 28 surrounds the front part of the pipe 26 and water is supplied thereto through a pipe 30 with the water exhausting therefrom through a pipe 32. Water is supplied to the casing l0 through pipes 34 and exhausts through a pipe 35. The usual valves are provided for regulating the flow of the various fluids.

The burner 8 may be located on the exact center line of the furnace or its axis may be tilted a slight amount toward the front of the furnace as shown. For example, it might be aimed at a point three feet from the longitudinal center line on the oppsite end wall of the furnace. The vertical angle of the burner is preferably such that the flame strikes the top of the bath 38 at a point in line with the center line of the first furance door 10. In addition to the door ltl, the front wall 42 is'provided with doors 44 and 46, the door 46 being on the center line of the furnace and two doors similar to doors 40 and 45. being located on the opposite side of the center line. The furnace is provided with the usual back wall 48. Air for combustion is supplied from the checker chamber 50 through air uptakes 52 and flows into the melting chamber 54 around the stream of fuel from burner 8. The mixing of the fuel and air is accelerated as it passes through the restricted passageway or throat 56.

The burner is operated as follows:

Metal scrap is charged into the furnace, the burner I2 is started in operation and oxygen is introduced through the pipe 26. The air from the checker chamber 50 flows upwardly through the uptake 52 around the streams of fuel flowing from the burner. The velocity of the oxygen stream is preferably approximately the same as the velocity of the flame but may vary from onesixth to two times the velocity of the flame, this being sufficient to enable the oxygen to penetrate the cone of the fuel stream flame at a point approximately 2 feet from the end of the fuel jet. By supplying oxygen in this manner the greatest amount of heat is directed downwardly on the charge where it is most useful. The oxygen is preferably turned 011 at the end of the melt-down period or at least a short time after the lime boil, but may if desired be used to raise the temperature of the molten bath after additions have been introduced while working the heat. It will be understood that the furnace will otherwise be operated in the usual manner. That is, it will be reversed at intervals and on each reversal, the burner and oxygen will be shut off at one end and the burner and oxygen at the other end will be turned on.

While one embodiment of my invention has been shown and described, it will be apparent that other adaptations and modifications may be made without departing from the scope of the following claims.

I claim:

1. A burner comprising a liquid fuel nozzle, conduits for delivering a liquid fuel and an atomizing agent to said nozzle, and an oxygen supply conduit entirely below said nozzle, said oxygen supply conduit extending between one inch and twelve inches beyond the end of said liquid fuel nozzle, the axis of the discharge end of said conduit being substantially parallel to the axis of said nozzle.

2'. A burner comprising a casing, a liquid fuel nozzle at the upper forward end of said casing, conduits for delivering a liquid fuel and an atomizing agent to said nozzle, and an oxygen supply conduit in the lower part of said casing, the end of said oxygen supply conduit extending between one inch and twelve inches beyond the end of said casing, the axis of the discharge end of said conduit being substantially parallel to the axis of said nozzle.

References Cited inthe file of this patent UNITED STATES PATENTS Number Name Date Re. 23,372 Crowe June 25, 1951 1,588,634 Wallstrom 1- June 15, 1926 1,630,509 Adams May 31, 1927 1,712,326 Brock May 7, 1929 2,446,511 Kerry Aug. 3, 1948 2,466,258 Morgan Apr. 5, 1949 2,532,711 Goddard Dec. 5, 1950 

